People can use various “modalities” when conversing with others. Examples of modalities include electronic mail (“e-mail”), instant messaging, voice conferencing or messaging, video conferencing or messaging, facsimile (“fax”), web pages, web logs (“blogs”), Internet newsgroups, and so forth. In fact, a conversation may employ multiple modalities. As an example, user A may request information from user B via an e-mail message. User B may then respond to the request by telephoning user A, such as by using a device that communicates by employing Voice over Internet Protocol (“VoIP”).
People sometimes provide contextual information, such as a common reference, so that the conversation can flow smoothly. During an oral exchange, for example, a person may remind another person about a conversation the two previously had. Users generally provide the common reference explicitly when using some electronic modalities (e.g., e-mail). As an example, when a sender sends an e-mail to a recipient, the recipient can reply to the message via e-mail. In such a case, the common reference can be the subject the sender identified in the e-mail message and the original text the sender typed into the e-mail message. The recipient's e-mail system may include the subject and this original text in the response.
Contextual information is conventionally not available to users when they use multiple modalities in a conversation. As a result, when users employ multiple modalities during a conversation, they may need to reestablish the common reference before beginning a meaningful dialog. As an example, when responding by telephone, user B may need to remind user A, who sends many e-mail messages, that user A previously sent an e-mail message to user B requesting information. User B may then proceed to provide the requested information orally by telephone. Users may even need to reestablish the common reference when they use a single modality, such as when using a modality that does not involve e-mail. When the responding user does not provide contextual information, the user initiating the conversation may find it difficult to recall what the conversation is about. This is especially true when one of the users carries on multiple conversations nearly simultaneously, such as via e-mail.
In some modalities, users must provide contextual information explicitly, such as by typing the information. As an example, when user A desires to discuss the contents of a document or a database record in an application with user B, user A must inform user B how to locate the document or database or provide some other indicative information so that user B has sufficient information to begin a meaningful conversation.